This application is in response to Notice Number (NOT-OD-10-036) "NIH Announces the Availability HIV/AIDS Funds for Competitive Revision Applications (R01) for HIV/AIDS-related Research through the NIH Basic Behavioral and Social Science Opportunity Network (OppNet)." HIV preventive interventions overwhelmingly use self-reports as their primary outcomes, a strategy that creates considerable skepticism of the validity of the outcomes of behavioral interventions. We propose to supplement the self-reported outcomes of an existing randomized controlled trial (RCT) with a suite of biomarkers that each reflect specific aspects of health status and together reflect physical health burden, or allostatic load. If allostatic load is lower in the intervention condition, we will have validity to self-report ratings of stress, mental health symptoms, and daily routines. These measures can then be used in a broad range of behavioral intervention trials to validate self-reports. A cluster RCT is being conducted in Cape Town, South Africa, to test the impact of the Philani Preventive Intervention (PIP). Pregnant women &their infants are randomized by neighborhood (N=24 neighborhoods) to: the PIP (8 home visits to all mothers at risk (MAR) who are living with HIV, using alcohol, depressed, or with underweight babies;n=340 MAR);or a standard care condition (clinic-based health care;N=340 MAR). Mothers are assessed during pregnancy, post-birth, 6 &18 months. The RCT has gone exceptionally well, having recruited over 532 MAR who are closely matched across conditions;achieved participation and follow- up rates well above 92%;high uptake of PIP (94% complete);and produced positive preliminary results in multiple domains (alcohol risk, social welfare, oral hydration, disclosure). These preliminary outcomes are encouraging;if mothers &infants in the PIP condition show significant reductions in risk and improvements in outcomes, there are existing funding lines in South Africa and the World Health Organization (WHO) to broadly adopt PIP's diffusion. PIP may also be relevant for the U.S.: health care reform currently allocated $1.5 billion for the nurse home-visiting program of Olds et al. (2002). PIP may be an alternative, evidence-based model. However, the present study relies solely on self report methods for assessing mental and physical health status, while biomarkers can provide a direct window onto both specific and global aspects of maternal functioning (Worthman &Costello, 2009). Additionally, inclusion of a more thorough evaluation of infant psychomotor development at 6 months would sharpen our understanding of the impact of the PIP on infant welfare via its effects on maternal health, general coping, &parenting behavior during a particularly vulnerable and important developmental period. Thus, strengthening evaluation of maternal and infant health effects of the PIP would increase our ability to test for outcomes with implications for long-term health of mother and child. PUBLIC HEALTH RELEVANCE: The preliminary outcomes are encouraging, yielding results that may be highly salient both for adoption in South Africa with existing funding lines for the Integrated Management of Childhood Disorders (IMCD) and for the U.S. The PIP closely resembles a highly effective U.S. home-visiting program (Olds et al., 2002) that has recently received $1.5 billion funding in health care reform. PIP may offer a model for a paraprofessional home visiting program that may be more cost-efficient than the currently adopted nurse model and more broadly applicable to a spectrum of new mothers including under-resourced settings and will be useful for a broad range of studies.